Method for treating vitreous materials by thermal poling

Abstract

The invention relates to a method for treating a silicate-type glass comprising alkali and alkaline-earth metal oxides or d 10 or IIIA metal oxides, said method comprising at least the following steps: (a) incorporation of nitrogen into the surface of the glass; and (b) thermal poling treatment of the material obtained in (a), under a chemically inert controlled atmosphere. The invention also relates to the material produced by said method.

The invention claimed is: 
     
       1. A method for treating a silicate-type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides, said method comprising:
 (a) incorporating nitrogen into a surface of the silicate-type glass whereby a material comprising nitrogen is obtained, and 
 (b) thermal poling treatment of the material comprising nitrogen from (a) under a chemically inert controlled atmosphere, 
 wherein the material comprising nitrogen is placed between an anode and a cathode without direct contact between the material comprising nitrogen and the anode. 
 
     
     
       2. The method according to  claim 1 , wherein (a) comprises a thermal treatment of the silicate-type glass at a temperature greater than or equal to 150° C. in a nitrogen-controlled atmosphere. 
     
     
       3. The method according to  claim 2 , wherein the temperature is 200° C. to 500° C. in (a). 
     
     
       4. The method according to  claim 2 , wherein in (a) the atmosphere comprises a gas selected from the group consisting of N 2  and NH 3 . 
     
     
       5. The method according to  claim 2 , wherein in (a) the atmosphere comprises nitrogen N 2 , or a mixture of nitrogen and an inert gas selected from the group consisting of Ar and He. 
     
     
       6. The method according to  claim 1 , wherein in (b) the material comprising nitrogen is maintained at a temperature ranging from 150 to 500° C. and exposed to an electric field having a voltage of 0.1 to 10 kV. 
     
     
       7. The method according to  claim 1 , wherein in (b), the controlled atmosphere consists essentially of a gas selected from the group consisting of dry air, O 2 , N 2 , Ar, He, and a mixture of two or more of these gases. 
     
     
       8. The method according to  claim 7 , wherein in (b) the controlled atmosphere consists essentially of N 2  nitrogen. 
     
     
       9. The method according to  claim 6 , wherein in (b) the material comprising nitrogen is maintained at a temperature of from 200 to 300° C. 
     
     
       10. The method according to  claim 1 , wherein the silicate-type glass has a mass composition of 0 to 40% Al 2 O 3 ; 50 to 97% SiO 2 ; 0 to 15% B 2 O 3 ; 0 to 25% ZnO; 0% to 5% ZrO 2 ; 0 to 10% TiO 2 ; 0 to 40% Na 2 O; 0 to 40% Li 2 O; 0 to 40% K 2 O; 0 to 40% MgO; 0 to 50% CaO; 0 to 40% SrO; 0 to 40% BaO; 0 to 15% Ag 2 O; 0 to 15% Au 2 O 3 , Au 2 O; 0 to 15% Cu 2 O, and at least 95% by weight of the components, relative to the total mass of the glass, that are selected from the group consisting of Al 2 O 3 ; SiO 2 ; B 2 O 3 ; ZnO; ZrO 2 ; TiO 2 ; Na 2 O; Li 2 O; K 2 O; MgO; CaO; SrO; BaO; Ag 2 O; Au 2 O 3 ; Au 2 O; and Cu 2 O. 
     
     
       11. The method according to  claim 1 , wherein the silicate-type glass used is a glass of the composition, defined in % by mass, of from 60 to 74% of SiO 2 , 8.2 to 16.4% of Na 2 O, 3.2 to 7.40% CaO, 2.8 to 4.30% MgO, 0.3 to 1.20% Al 2 O 3 , 0.3 to 1.20% K 2 O and 0.1 to 0.30% SO 3 . 
     
     
       12. A method for
 improving durability of glazing of a silicate-type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides; or 
 improving scratch resistance of a digital/tactile screen comprising alkali and alkaline earth metal oxides or IIIA metal oxides; or 
 increasing resistance to abrasion of a mirror comprising alkali and alkaline earth metal oxides or IIIA metal oxides; 
 said method comprising: 
 (a) incorporating nitrogen into a surface of the silicate-type glass whereby a material comprising nitrogen is obtained, and 
 (b) thermal poling treatment of the material comprising nitrogen from (a) under a chemically inert controlled atmosphere, 
 wherein the material comprising nitrogen is placed between an anode and a cathode without direct contact between the material comprising nitrogen and the anode. 
 
     
     
       13. A method of manufacturing:
 a building glazing comprising a silicate-type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides; or 
 a solar panel mirror comprising a silicate-type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides; or 
 a screen for electronic devices comprising a silicate-type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides; or 
 a fiberglass comprising a silicate: type glass comprising alkali and alkaline earth metal oxides or IIIA metal oxides; 
 said method comprising: 
 (a) incorporating nitrogen into a surface of the silicate-type glass whereby a material comprising nitrogen is obtained, and 
 (b) thermal poling treatment of the material comprising nitrogen from (a) under a chemically inert controlled atmosphere, 
 wherein the material comprising nitrogen is placed between an anode and a cathode without direct contact between the material comprising nitrogen and the anode.